A. Field of the Invention
This invention generally relates to a mechanical gripper for holding a part, and more particularly, to a gripper for holding turbine blades on a conveyor system and in an X-ray inspection system.
B. Background Discussion
An X-ray inspection system for inspecting turbine blades includes a conveyor belt for transporting the blades from an operator loading station to an inspection station. The blades inspected are generally small in shape, typically less than 3 inches in diameter and less than 9 inches high. The manufacture of the blades has led to the development of blades containing complex interior passages and openings to the blade surface for blade cooling. An automated digital X-ray inspection system has been developed for the turbine blade inspection.
The X-ray inspection system is comprised of hardware for manipulating parts, generating X-rays, detecting X-rays, hardware for information transmission and computation, and software for controlling the software imaging system. Parts are carried into the X-ray machine by a multi-station conveyor. When the conveyor advances the blades to an inspection station, a numerically controlled part manipulator seizes the part and moves it to an inspection site between the X-ray beam and the X-ray detector. The X-ray inspection system then computes a digital fluoroscopy image while the part is moved vertically through the X-ray beam. In addition, a computed tomography image is generated with a part held in a constant vertical position and rotated through 360 degrees by the part manipulator. After imaging, the manipulator moves the part to the conveyor station and the conveyor station transports the part to an unload station for the operator.
It is an object of this invention to provide universal grippers which hold the turbine blade on the conveyor.
It is a further object of this invention to provide a gripper which can be mechanially connected to the part manipulator and moved up into the X-ray beam.
It is a further object of this invention to provide a gripper with an exact center of rotation aligned with the center of rotation of the part manipulator.
It is a further object of this invention to provide a gripper that fits in a pallet on the conveyor belt, but is easily seized by the part manipulator for transporting to the X-ray inspection site.
It is another object of this invention to provide a gripper for an X-ray inspection station with low attenuation material in the jaws.